A myth is defined as a story with no explainable or historical basis in fact. It is normally based upon a past tradition, often of a scientific, religious or historical nature, that is invented or imaginary. Myths are somewhat synonymous with legends--fictitious tales that have been passed down for generations and cannot be proven. The word is derived from the Greek word "mythos" ("word story"); most myths originated in a spoken form which did not include written, factual varifcation. The word is also closely related to the word fable, but most myths do contain a religious or divine implication; legends and fables are generally of a more human, flesh-and-blood nature.